In a manufacturing process of a semiconductor device, after IC chips are manufactured, reliability of each individual chip is determined by performing various inspections of electrical characteristics on a wafer. A probe apparatus for performing the inspections is configured to mount a wafer on a mounting table; to align positions of the wafer and probe needles of a probe card; and to bring the probe needles to make contacts with electrode pads of the IC chips on the wafer. Conventionally, so-called “bent or horizontal needle” was mainly used as the probe needle, however, accompanying with high integration and miniaturization of IC chips, a vertical needle which contributes to arranging probes in a high density is widely used.
However, in a contact operation for contacting the electrode pads with the probe needles, it is required to rend a native oxide film formed on the surface of the electrode pad by the probe needle to secure a reliable electrical contact therebetween. Further, after the contact operation, a confirmation process is preformed to confirm whether a right contact was made or not by imaging needle marks with a camera. For an easy confirmation, it is also required to leave a reasonable size of the needle mark.
FIG. 7A shows probe needles (bent or horizontal needles) 101 diagonally extending downwards from a probe card 102 and FIG. 7B shows contact statuses in case of using the probe needles 101. First, a mounting table is moved upwards, whereby the probe needle 101 makes a contact with an electrode pad 103 (dotted lines in FIG. 7B). Thereafter, when the mounting table is further moved upwards slightly (to perform so-called “overdriving”), the probe needle 101 is bent and a tip thereof slides to a side, whereby a native oxide film 105 formed on the surface of the electrode pad 103 is rended (solid lines in FIG. 7B). Therefore, the probe needle 101 can be securely contacted with the electrode pad 103, and the needle mark confirmation process can be facilitated.
Meanwhile, FIG. 8A shows probe needles 104 vertically extending downwards from a probe card 102. When a rising speed of a wafer is so fast during an overdriving, a tip of the probe needles 104 can rend the electrode pad 103, whereby IC chips can be damaged. Further, the probe needles 104 also can be damaged by an impact caused by the contact of the probe needle 104 and the electrode pad 103. Therefore, a wafer needs to be raised gently during the overdriving. However, since the probe needles 104 stretch out vertically and heights of the tips thereof are not exactly same, the probe needle 104 may not penetrate through or rend the native oxide film 105, thereby resulting in a poor conductivity. Further, a great force can be applied to the electrode pad 103 and the probe needle 104 in a vertical direction, so that the probe needle 104 and/or the IC chips can get damaged. Furthermore, since a needle mark formed on the electrode pad 103 is a point, it is difficult to perform image recognition.
Japanese Patent Laid-open Application No. H6-124985 (especially para. 0011) discloses a technique in which a wafer is moved in a horizontal direction after performing overdriving of the vertical probe needles 104. However, as shown in FIG. 8B, the probe needle 104 is stuck into the electrode pad 103 by the overdriving. Therefore, when the electrode pad 103 moves in a horizontal direction the probe needle 104 may be bent without tearing the native oxide film 105. Moreover, probe needles 104 can be damaged.